We have recently succeeded in isolating neuronal and glial clones by transforming rat cerebellar cells with Rous sarcoma virus which is temperature-sensitive for transformation (ts-RSV) (Giotta, G. J., J. Heitzmann, and M. Cohn, submitted for publication). In the coming year we propose to identify the cerebellar cell types that the ts-RSV transformed cell lines represent. This will consist of 1) determining the neurotransmitter content, enzymes involved in neurotransmitter synthesis, and the types of neurotransmitter high-affinity uptake systems present in the various cell lines, and 2) the use of immunological methods to identify cell surface and cytoplasmic markers unique to specific classes of cerebellar neuronal and glial cells.